Securing device for a removable bag for a centrifuge

ABSTRACT

A securing device for a removable bag for a centrifuge having a vertical axis for its basket provided with a central cone, the bag comprising an outer cylindrical part to fit the outside wall of the basket, an intermediate part to fit the bottom of the basket, and a truncated conical part to fit the central cone and provided with a central opening. The securing device is constituted by a circular skirt to fit inside the perimeter of the basket, the skirt being connected to the upper edge of the cylindrical part of the bag, a crown to which the skirt is fixed, and a cruciform member connected to the edge of the central opening of the bag. A lifting assembly adapted to be suspended from a hoist can be detachably connected to the crown, the lifting assembly also being detachably engageable with the cruciform member. The device may either be supported on feet at a discharge station, with a central sliding rod of the lifting assembly then permitting the central opening of the bag to fall, or a manually operated lever may be provided on the lifting assembly to effect release of the central opening to permit it to fall.

taes atertt 1' ousselet SECURING DEVICE FOR A REMUVABLE BAG FOR A CENTRllFlUGE [75] Inventor: .loseph Roussellet, Annonay, France [73] Assignee: Establissements Rousselet,

Montalinet, Annonay, Ardeche, France [22] Filed: Aug. 27, 11971 [21] Appl. No: 175,551

[30] Foreign Application Priority Data Krantz et a1 210/232 X [111 BfiAd [451 Jan. 29, 1974 Primary Examiner-Samih N. Zaharna Assistant Examiner-F. F. Calvetti Attorney, Agent, or FirmEric H. Waters et a1.

[ 5 7] ABSTRACT A securing device for a removable bag for a centrifuge having a vertical axis for its basket provided with a central cone, the bag comprising an outer cylindrical part to fit the outside wall of the basket, an intermediate part to fit the bottom of the basket, and a truncated conical part to fit the central cone and provided with a central opening. The securing device is constituted by a circular skirt to fit inside the perimeter of the basket, the skirt being connected to the upper edge of the cylindrical part of the bag, a crown to which the skirt is fixed, and a cruciform member connected to the edge of the central opening of the bag. A lifting assembly adapted to be suspended from a hoist can be detachably connected to the crown, the lifting assembly also being detachably engageable with the cruciform member. The device may either be supported on feet at a discharge station, with a central sliding rod of the lifting assembly then permitting the central opening of the bag to fall. or a manually operated lever may be provided on the lifting assembly to effect release of the central opening to permit it to fall.

5 Claims, 6 Drawing Figures PATENTHJJM 29 1914 SHEET 2 OF 4 PATENTEDJAH 29 I974 3. 788A8O SNkH 3 m 4 FIGS f l SECURING DEVICE FOR A REMOVABLE BAG FOR A CENTRIFUGE This invention relates to a securing device for a removable bag for a centrifuge.

For filtering and emptying by downward discharge the sediments that collect in a centrifuge, there is often used a bag consisting of a cylindrical outer part, an intermediate part, and a truncated conical part fitting itself to the wall of the central cone of the centrifuge and provided with a central opening.

The assembly used to secure the central truncated conical part, in a manner enabling the latter to be detached for emptying, necessitates manual operations that are particularly difficult in the case of centrifuges of large size.

Usually, the securing is effected by rings or a grooved rim with a cord therearound it, such that the manual operations are very laborious in centrifuges of large diameter, because the operator can only reach the central axis with difficulty. Moreover, when emptying, the action becomes even more difficult because the usually considerable height at which the bag is disposed makes it difficult to reach the rings of the central part to disengage the lifting hook or to detach the cord, owing to the charge of material and likewise the risk of accident.

The present invention is directed to a securing device for the removable bag for a centrifuge, the device ensuring the automatic centering of the bag and making unnecessary any manual action for putting it in position in the rotatable basket or bowl of the centrifuge, and likewise for removing the bag when the material has to be discharged.

This device consists on the one hand of a circular skirt which, upon fitting into the opening of the basket or bowl, is fastened to the upper edge of the outer cylindrical part of 'the bag, and is integral with a crown adapted to be fastened to annular means and/or hooks of the upper part of a lifting assembly hooked to a hoist, and on the other hand, a crosspiece connected to the edge of the central opening of the bag and comprising hook means adpated to cooperate with a hooking finger disposed in the central part of the lifting assembly.

The accompanyingdiagrammatic drawings show by way of example two embodiments of the device.

FIGS. 1, 2 and 3 are part-sectional views showing a first embodiment of the device when the bag is respectively in its operative position in the drum of the centrifuge, after lifting from the drum, and in discharging position;

FIG. 4 is a fragmentary plan in a section taken on the line 4-4 of FIG.. 3, showing more particularly the crosspiece of the device;

FIG. 5 is a view corresponding to FIG. 1, but showing another embodiment of the device; and

FIG. 6 is a part-sectional front elevation, showing at its leftand right-hand sides respectively the bag first as it is being engaged and then during emptying.

In FIG. 1, there is seen an outer casing or shroud l of a conventional vertical centrifuge. as well as a movable basket or bowl 2, the basket having a large upper opening. According to the invention, a removable crown 3 just fits inside this opening in the basket and supports a bag 4 secured by means of girdles on a circular skirt 5 of the crown 3. On this crown 3 hooks 6 are fixed. The bag is folded back in it central part, and,

2 when it is in position in the centrifuge, it takes the shape of the generally conical wall of the drum. The central part of the bag is connected to a rigid ring 7 of metal or other material, integral with a cruciform member 8 with hooks 9.

Another cruciform member 10 serves for the hooking and manipulation. It has a central hole 11 and rings or hooks 12 adapted to come into hooked engagement with the hooks 6 on the crown 3.

At an emptying station, vertical supports 13 are secured to the floor and are connected together by a ring on which the cruciform member 10 rests at the time of emptying.

Through the central hole 11 passes a sliding vertical rod 14 of polygonal section, here shown as of square section, carrying at its upper end a ring to be hooked on a hook 16 of a manipulating hoist.

The rod also carries at its lower end hooking fingers 17 that fit into the hooks 9 of the cruciform member 8 disposed at the lower part of the bag. Radial fingers l8 fixed on the cruciform member 10 ensure guiding of the sliding rod l4 andradial abutment fingers 19 ensure the lifting of the cruciform member when they come into contact with it.

The assembly of the cruciform member 10 and the rod 14 always remain suspended from the hoist ready to take part in the manipulation. It is thus easy to understand the cycle of manipulation. Thus, the assembly of cruciform member 10 and rod 14 suspended from the hoist is brought above the drum of the centrifuge so as to be hooked, by a slight pivoting of the assembly, to the hooks 6 of the crown 3, as well as to the hooks 9 of the cruciform member 8 (FIG. 2).

The assembly is then lifted by the hoist; the crown 3 is withdrawn from the basket of the centrifuge and carried to a position above the emptying station and feet 13.

When lowered by the hoist, the cruciform member 10 comes to rest on the ring connecting the feet 13 and the sliding of the rod 14 allows the bag to elongate vertically, for emptying, by downward discharge, the centrifuged material above the desired point of discharge.

FIG. 4 shows a part of the arms of the cruciform member 10, the square section of the central rod 14, and the four guide fingers 118, which allow, by having their sides chamfered, the central rod 14 to turn somewhat about its axis in order for the fingers 17 to engage in the hooks 9, as well as for the cruciform member 10 to pivot for the engagement with the hooks 6, all without any hand manipulation of the central hooks, which are difficult to reach, especially with a drum of large diameter.

In another embodiment, shown in FIGS. 5 and 6, the crown 3 of the bag 4 carries rings 20 in which can be engaged hooks 22 integral with a crosspiece 23 provided at its central part with means 24 such as a stub axle to provide for engagement with the hook of a hoist or other lifting means. The crosspiece 23 also carries at its central part a hooking finger 25 pivoted to crosspiece 23 at 26 and including an integral radially extending lever 27 urged upwardly by a spring 28. At the free end of the lever 27 is hooked a controlling rope of a length depending on the lifting height of the hoist.

As in the previous embodiment, the central part of the basket is integral with a metal ring 7 that is connected to a small cruciform member 8. However, in this embodiment, the cruciform member 8 carries only one hook 30 adapted to co-operate with the hooking finger 25.

In addition, the cruciform member 8 carries hooks 32 pivoted thereto at 33 and adapted, when the bag 4 is disposed in the basket 2 of the centrifuge, to engage by centrifugal force against an internal lip 34 of the central part of the basket. This lip 34 is shown more particularly in FIG. 5.

To remove the bag 4 from the basket 2, it is only necessary, as will be clear from FIG. 5, to lower the lifting assembly into the opening of the basket until the hooking finger 25 automatically engages with the hook 30, then to pivot the assembly for the hooks 22 of the crosspiece 23 to engage the rings 20 of the crown 3. At this stage, the bag 4 can be extracted from the centrifuge and taken to the discharge station, which as shown in FIG. 6, needs no external support to receive the bag. Instead, to effect emptying of the bag, it is not necessary to place the assembly onto a support, it simply being a matter of operating the control rope 29 in the direction of the arrow 35 (FIG. This causes the finger 25 to move to the position shown in dotted lines in F IG. 6, and thus automatically to free the hook 30, the cruciform member 8, and, in consequence, the central part of the bag 4, which, under the weight of the sediment, takes the position shown at the right-hand side of FIG. 6.

What I claim is:

l. A securing device for a removable bag for a centrifuge of the type having an open basket with a vertical axis and a central cone, inside of which basket is disposed a removable flexible bag adapted to collect sediment, the bag having an outer cylindrical part, an intermediate part, and a truncated conical part resting on the central cone of the centrifuge and provided with a central opening, said securing device comprising a circular skirt ofa size enabling it to be fitted into the open basket, means for connecting the skirt to the cylindrical part of the bag at the upper edge thereof, a crown secured to said skirt and including means for detachable connection to a lifting assembly suspended from a hoist, a cruciform member connected to the truncated conical part of the bag at the edge of the central opening therein, at least one hook on said cruciform member for engaging the lifting assembly such that with the lifting assembly connected to the crown and the cruciform member, the latter can be lifted from the basket with the bag maintaining its position whereafter by lowering the cruciform member, the central opening in the bag can be lowered to a discharge position, said lifting assembly includes a crosspiece disposed above the bag, said means on the crown for detachable connection with the lifting assembly includes members detachably engagable with the crosspiece, a central hooking finger pivotably connected to the crosspiece and adapted to engage the hook of the cruciform member, and means coupled to said hooking finger to pivotably move the same for selectively releasing the hook on the cruciform member to allow the bag to lower to its discharge position.

2. A device according to claim 1 wherein said means on the crown for detachable connection with the lifting assembly comprises hooks adapted to be engaged in complementary hooks carried by the crosspiece of the lifting assembly.

3. A device according to claim 1 wherein the means coupled to the hooking finger comprises a radial lever secured thereto, spring means acting on said lever to urge the hooking finger into an engaged position in the hook on the cruciform member, and a control member extending from said lever to displace the same against the action of the spring means to release the hook and allow the bag to drop by gravity to its open position.

4. A device as claimed in claim 3 wherein said control member is a rope depending from the lever at a free end thereof and disposed outside the outer portion of the bag.

5. A device as claimed in claim 1 comprising hook members pivotably connected to said cruciform member and freely depending therefrom for engaging the central cone of the basket under the action of centrifugal force. 

1. A securing device for a removable bag for a centrifuge of the type having an open basket with a vertical axis and a central cone, inside of which basket is disposed a removable flexible bag adapted to collect sediment, the bag having an outer cylindrical part, an intermediate part, and a truncated conical part resting on the central cone of the centrifuge and provided with a central opening, said securing device comprising a circular skirt of a size enabling it to be fitted into the open basket, means for connecting the skirt to the cylindrical part of the bag at the upper edge thereof, a crown secured to said skirt and including means for detachable connection to a lifting assembly suspended from a hoist, a cruciform member connected to the truncated conical part of the bag at the edge of the central opening therein, at least one hook on said cruciform member for engaging the lifting assembly such that with the lifting assembly connected to the crown and the cruciform member, the latter can be lifted from the basket with the bag maintaining its position whereafter by lowering the cruciform member, the central opening in the bag can be lowered to a discharge position, said lifting assembly includes a crosspiece disposed above the bag, said means on the crown for detachable connection with the lifting assembly includes members detachably engagable with the crosspiece, a central hooking finger pivotably connected to the crosspiece and adapted to engage the hook of the cruciform member, and means coupled to said hooking finger to pivotably move the same for selectively releasing the hook on the cruciform member to allow the bag to lower to its discharge position.
 2. A device according to claim 1 wherein said means on the crown for detachable connection with the lifting assembly comprises hooks adapted to be engaged in complementary hooks carried by the crosspiece of the lifting assembly.
 3. A device according to claim 1 wherein the means coupled to the hooking finger comprises a radial lever secured thereto, spring means acting on said lever to urge the hooking finger into an engaged position in the hook on the cruciform member, and a control member extending from said lever to displace the same against the action of the spring means to releaSe the hook and allow the bag to drop by gravity to its open position.
 4. A device as claimed in claim 3 wherein said control member is a rope depending from the lever at a free end thereof and disposed outside the outer portion of the bag.
 5. A device as claimed in claim 1 comprising hook members pivotably connected to said cruciform member and freely depending therefrom for engaging the central cone of the basket under the action of centrifugal force. 